Method for the treatment of sticky cotton fiber with enzymes

Abstract: An enzyme composition, use thereof in a method for reducing the stickiness of honeydew contaminated cotton is disclosed. The composition includes, and the method uses, enzymes such as transglucosidases and pectinases capable of hydrolyzing sugars that make-up honeydew, which are derived from fungal sources, such as fungi of the genus Aspergillus .

Description: Field of the Invention The present invention relates to the treatment of "Sticky Cotton" for the reduction of the stickiness on the cotton fibers and, in particular, to enzyme compositions and methods using such enzyme compositions for the treatment of "Sticky Cotton" fiber in order to obtain a reduction of the stickiness thereof. Background of the Invention "Sticky cotton" is a term used to refer to cotton fiber that has thereon sticky sugar deposits which have been excreted by certain (homopteran) insects (mainly the sweet potato whitefly Bemisia tabaci and the cotton aphid, Aphis gossyppi) which feed on cotton leaves above open bolls. Sticky cotton causes severe problems during the milling of cotton. It is a problem faced by cotton growers all over the world. The sticky substance on the cotton fibers of "Sticky cotton" is called "honeydew". Honeydew is a complex mixture of mono-, di-, trisaccharides and small amounts of protein and organic acids (1,2). A typical composition of the honeydew produced by white flies is 29.5 % oligosaccharides (including melezitose), 10.1 % sucrose, 5.3 % glucose, 11.7 % fructose, and 43.1 % trehalulose (3). Honeydew on cotton makes it difficult to process the cotton in gins and textile mills. Furthermore, the presence of such honeydew enhances the microbial fermentation of fiber staining fungi which greatly deleteriously effects the fiber quality of the cotton. In gins, sticky cotton interferes with trash removal and requires gin blades to be cleaned more frequently, slowing the ginning operation. This can significantly reduce productivity. In textile mills, honeydew interferes with the major processing steps including carding, drawing, roving and spinning operations. Because of the adaptation of high speed technology, sticky cotton is a major threat to cotton production in many countries and plays an important quality consideration in the textile industry. There seems to be limited work reported in reducing the stickiness of infected cotton. Heating the sticky cotton to 130-140 °C for a short time was reported to caramelize the sugars in honeydew to avoid stickiness during spinning (4). The application of a hydrocarbon and surfactant additive to the cotton was reported to eliminate the sticking problem in yarn manufacturing (5). Another approach which has been reported is to spray contaminated cotton bales with dilute solutions of ammonium hydroxide or ammonium nitrate to enhance microbial breakdown of the sugars in honeydew (2). Others have indicated the use of insecticides to control cotton stickiness (6,7). The use of a material called Tempanil®, reported to contain glucose oxidase, applied to contaminated cotton was found to significantly decrease soluble sugars (8). The change in stickiness of the treated cotton was not mentioned. Tempanil® consists of two parts : a powdered preparation of glucose oxidase and catalase; and, a liquid mixture of non-ionic and anionic wetting agents. From the literature it can be seen very little has been done in the area of using enzymes to hydrolyze honeydew, except for the use of glucose oxidase. However, glucose oxidase only converts glucose to gluconic acid, and is not active on those sugars which are known to contribute to the stickiness of the cotton. The complex low molecular weight di- and tri-saccharides i.e. trehalulose and melezitose, which are present in honeydew, contribute significantly to the stickiness of the contaminated cotton. These sugars contain simple sugars, glucose and fructose, which are linked by alpha and beta glucosidic linkages as given below : (1) Trehalulose (0-α-D-glucopyranosyl - (1→1)-D-fructofuranoside) (2) Melezitose (0-α-D-glucopyranosyl-0-(1-2)-0-β-D-fructofuranosyl-(3-1)-α-D-glucopyranoside) Unfortunately, the trehalulose and melezitose which are present in honeydew are resistant to hydrolysis by conventional carbohydrate hydrolyzing enzymes. Thus, the use of such conventional carbohydrate hydrolyzing enzymes does not satisfactorily treat sticky cotton by the removal of honeydew from the fibers thereof. Accordingly, it can be seen that there remains a need to provide a composition, and in particular an enzyme composition, which is capable of hydrolyzing, or otherwise reducing, the honeydew on cotton fiber. It can further be seen that there also remains a need for a method, using such an enzyme composition, for the treatment of sticky cotton fiber in order to effect a reduction in the stickiness thereon. DE-A-946881 discloses a method for treating raw cotton employing pectinase. DE-A-3635427 discloses a phosphate-free washing composition containing pectinase. JP-A-62299504 and JP-A-62223309 disclose an apparatus and method to treating honeydew on cotton. The method employs a composition containing yeast and an enzyme such as glucamylase or gamma-amylase. Accordingly, in one aspect, the present invention provides the use of at least one enzyme which is a transglucosidase, a pectinase or an α-galactosidase for the reduction of honeydew on sticky cotton contaminated with honeydew. In accordance with the teachings of the present invention, disclosed herein is a method for the treatment of cotton fiber having honeydew thereon, said method comprising contacting said cotton fiber with an enzymatic composition including at least one enzyme which is a transglucosidase, a pectinase or an α-galactosidase and is capable of hydrolyzing at least one of the honeydew sugars of contaminated sticky cotton, whereby the honeydew is at least partially hydrolyzed and a reduction of the honeydew on the contaminated cotton is provided. Preferably, the enzymatic composition includes at least one hydrolyzing enzyme derived from a fungal source. Preferably, the use and method employs enzymatic compositions having hydrolyzing enzymes which are derived from fungal strains of the genus Aspergillus. More preferably, such hydrolyzing enzymes are derived from strains of the species Aspergillus niger. Most preferred are hydrolyzing enzymes derived from the fungal strain Aspergillus niger (foetidus) which has been deposited in the American Type Culture Collection (ATCC) under accession number 14916. The preferred hydrolyzing enzymes derived from fungal sources to be included in the enzyme compositions of the present invention include transglucosidase (α-1,4 and α-1,6) and pectinase. These and further objects and advantages of the present invention will become readily apparent from a reading of the following description, taken in conjunction with the enclosed drawings. Brief Description of the Drawings Figures 1A and 1B are HPLC chromatograms of the honeydew digest at, respectively, zero time and seventeen (17) hours, resulting from the enzyme hydrolysis test of honeydew extracted from sticky (contaminated) cotton fiber conducted, as described in Example 1. Figures 2A, 2B, 2C and 2D are HPLC chromatograms of trans-glucosidase hydrolysis of sucrose at, respectively, zero time, one (1) hour, four (4) hours and twenty (20) hours, as described in Example 2. Figures 3A, 3B, 3C and 3D are HPLC chromatograms of trans-glucosidase hydrolysis of melezitose at, respectively, zero time, one (1) hour, four (4) hours and twenty (20) hours, as described in Example 2. Figures 4A and 4B are HPLC chromatograms of transglucosidase hydolysis of trehalulose at, respectively, zero time and four (4) hours, as described in Example 2. Figure 5A and 5B are HPLC chromatograms of the sugars extracted from fiber treated with a pectinase preparation derived from A. Niger . "Untreated" refers to the check sample in Table 2. "Boom + Duct" refers to the same replicates in both illustrations. Figure 6 is a chart demonstrating the efficacy of an enzymatic composition of the present invention, wherein the Y-axis is the Thermodetector Rating, the X-axis is the percent water in seedcotton, the solid (or black) dots and the line joining them together represents the results obtained from the use of an enzymatic composition containing 1 % (v/v) of the transglucosidase L-1000 preparation, the empty (or white) dots and the line joining them together represents the results obtained from the use of an enzymatic composition containing 2 % (v/v) of the transglucosidase L-1000 preparation and the triangles and the line joining them together represents the results obtained from the use of a standard. Figure 7 is a chart demonstrating the efficacy of an enzymatic composition of the present invention, wherein the Y-axis is the Minicard Rating, the X-axis is the percent water in seedcotton, the solid (or black) dots and the line joining them together represents the results obtained from the use of an enzymatic composition containing 1 % (v/v) of the transglucosidase L-1000 preparation, the empty (or white) dots and the line joining them together represents the results obtained from the use of an enzymatic composition containing 2 % (v/v) of the transglucosidase L-1000 preparation and the triangles and the line joining them together represents the results obtained from the use of a standard. Figure 8 is a chart demonstrating the efficacy of an enzymatic composition of the present invention, wherein the Y-axis is the Thermodetector Reading and the X-axis is the Minicard Reading. Figure 9 is a bar graph further demonstrating the efficacy of an enzyme composition of the present invention containing the transglucosidase L-1000 preparation which has been sprayed to various moisture levels and incubated for two weeks, wherein the X-axis is the Thermodetector Reading, and further wherein the lefthandmost bar represents a dry check (that is to say, a check of a sample having neither moisture nor enzyme), wherein the bar immediately to the right thereof represents a wet check having 10 % (v/v) H 2 O and no enzyme, wherein the bar immediately to the right thereof represents a wet check having 10 % (v/v) H 2 O and 0.26 % (v/v) of the transglucosidase L-1000 preparation, wherein the bar immediately to the right thereof represents a wet check having 12 % (v/v) H 2 O and 0.25 % (v/v) of the transglucosidase L-1000 preparation, wherein the bar immediately to the right thereof represents a wet check having 10 % (v/v) H 2 O and 0.5 % (v/v) of the transglucosidase L-1000 preparation, and wherein the bar immediately to the right thereof (the righthandmost bar) represents a wet check having 12 % (v/v) H 2 O and 0.5 % (v/v) of the transglucosidase L-1000 preparation. Detailed Description of the Invention The novel enzyme preparations (compositions) of the present invention include enzyme(s) capable of reducing the stickiness on cotton fiber by hydrolyzing sugars in honeydew, preferably, melezitose and trehalulose. Further, the method of enzymatic hydrolysis of these sugars, as disclosed herein, results in the reduction of the stickiness of the contaminated cotton. Thereby offering a simple, economical and safe solution to the major problem of the cotton growers all over the world. The enzymes which we have identified as being capable of such hydrolysis are those hydrolyzing enzymes which have been derived from a fungal source and, more particularly, fungi of the genus Aspergillus . Most preferred are those hydrolyzing enzymes which have been derived from strains of Aspergillus niger, such as that strain of Aspergillus niger (foetidus) which has been deposited in the American Type Culture Collection (ATCC) under accession number 14916. The types of hydrolyzing enzymes of the present invention which, when incorporated into the enzyme compositions of the present invention are capable of hydrolyzing sugars (melezitose and trehalulose) include transglucosidases, pectinases, and α-galactosidases which may have been derived from a fungal source. Examples of such transglucosidases are transglucosidase α-1,4 derived from A. niger ATCC 14916, transglucosidase α-1,6 derived from A. niger ATCC 14916 and that transglucosidase composition marketed under the tradename Transglucosidase L-1000 (SOLVAY ENZYMES, INC., Elkhart, Ind.). Examples of such pectinases are those pectinase compositions marketed under the tradenames PEAREX 5X and CLAREX-ML (SOLVAY ENZYMES, INC., Elkhart, Ind., U.S.A.). An example of an α-galactosidase is that α-galactosidase derived from A. niger (marketed under the tradename BEANO, by AK PARMA INC., USA). In accordance with the principles of the present invention, the hydrolyzing enzymes are used to prepare an enzyme composition for the hydrolysis of honeydew on cotton fiber, whereby the stickiness of the cotton fiber is reduced. In this regard, the enzyme (or enzymatic preparation) may be mixed or otherwise formulated with an acceptable carrier which permits the application of the resulting enzyme composition on the cotton fibers in such a manner that the honeydew thereon may be hydrolyzed thereby and removed therefrom. Example of carriers which may be utilized in the enzyme compositions of the present invention include water. Other types of carriers would include, wetting agents, such as TRITON® X-100 (UNION CARBIDE). The precise carrier to utilize may be varied depending upon the circumstances of the application (such as the desired contact time, environmental conditions during contact, etc.) of the enzymatic composition during use. The precise concentrations and ratios of the enzyme or enzymatic composition to carrier to be utilized in the preparation of the enzyme compositions of the present invention is well within the skill of the art to determine. Preferrably, the enzyme (or enzymatic preparation) is mixed with the carrier using methods, such as agitation, which are well-known in the art to dissolve and/or otherwise throroughly and substantially homogenously blend the components into a substantially homogenous composition. In further accordance with the principles of the present invention, the enzyme compositions of the present invention may be used for the treatment of cotton fiber having honeydew thereon. This method of treatment includes contacting the cotton fiber with the enzymatic compositions of the present invention for a time sufficient to permit at least partial hydrolysis of the honeydew. This method of treatment further includes the subsequent removal of the cotton fiber from the enzymatic composition, whereby the hydrolyzed honeydew remains in the enzymatic composition. In this manner, a reduction of the honeydew on the cotton fiber is provided. As described above, the enzymatic composition and the method for the use thereof of the present invention may be used to either treat cotton fiber which is still in the field or which has already been harvested. In the former case, the enzymatic composition may be applied with booms or any other suitable apparatus, such as sprayers, which are capable of distributing (preferrably, substantially evenly distributing) the liquid enzyme compositions onto the cotton fiber. In such a case, it is contemplated that the cotton fiber may then be removed from the enzymatic composition by both gravity causing the enzymatic composition to drip off the cotton fiber, by evaporation and by natural precipitation. If desired, subsequent wetting or soaking of the cotton fiber (before and/or after the harvesting thereof) may be also be resorted to for further removal of the enzymatic composition of the present invention from the cotton fiber being treated therewith. In the latter case, the enzymatic composition may be applied by soaking the harvested cotton fiber in an appropriate reservoir which contains the enzymatic composition of the present invention. Alternatively, the enzymatic composition may be applied by being sprayed onto the cotton fiber with the use of a suitable (and ordinary) apparatus, such as a air-pressure spray gun. Also, merely pouring the enzymatic composition over the cotton fiber would suffice. Once again, it is contemplated that the cotton fiber may then be removed from the enzymatic composition by gravity causing the enzymatic composition to drip off the cotton fiber, evaporation, natural precipitation and/or subsequent wetting or soaking of the cotton fiber for further removal of the enzymatic composition of the present invention from the cotton fiber being treated therewith. The length of time with which the enzymatic composition should stay in contact with the cotton fiber having honeydew thereon will vary, as can be readily determined by those skilled in the art, depending upon, inter alia , the quantity and throughness of hydrolyzation desired. It is contemplated herein that such contact may occur for as little as ten minutes or for as long as one desires, with contact times for up to several days or weeks being possible. However, it is contemplated herein that a minimun contact time of eighteen hours is preferred. Having generally described the composition and the method of the present invention, reference is now had to the following examples which are presented merely for illustration and should not be considered limiting. Example 1 A 15 gm sample of Cotton contaminated with honeydew was extracted with 600 ml water at 50 °C. The extraction was repeated for another three times. Each extraction involved wetting the cotton and mixing for 15 minutes and squeezing the water from the cotton by hand. The extracts were combined and concentrated in vacuum in a rotary film evaporator to about 10 ml. This extract was then used to screen for enzymes that would hydrolyze the honeydew. To test for hydrolyzing enzyme activity, 0.5 ml extract at pH 4.5 was incubated for 18 hours at 50 °C with 0.02 ml of transglucosidase L-1000 preparation, produced by a selected strain of Aspergillus niger which has been deposited in the American Type Culture Collection, Rockville, Maryland, U.S.A., under accession number ATCC 14916, (this strain is sometimes classified as being a member of the species Aspergillus foetidus ) and which has been cultured in an appropriate nutrient broth. The reaction was terminated by removing 0.2 ml sample of the reaction and placing it in a boiling water bath for 10 minutes. After cooling, 0.3 ml of 0.01 N H 2 SO 4 was added. This mixture was then centrifuged with an Eppendorf table top centrifuge, and the supernatant was clearified by filtration through a 0.45 micron filter. HPLC separation was then conducted on a 0.02 ml sample run on BioRad HPX-87H column (Bio-Rad USA) at 60 °C, using a mobile phase (0.01 N H 2 SO 4 ) flow rate of 0.7 ml/min. An Erma RI detector Model ER-7512 (Erma CA. Inc. Tokyo, Japan) was used for detection of sugars. The honeydew extract separated into peaks with glucose and fructose being the last two peaks. The conditions of separation in the column, low pH and high temperature cause sucrose to hydrolyze. The fate of sucrose in the presence of enzyme will not be fully understood under the conditions employed in HPLC. From the literature the composition of the oligosaccharides in honeydew is mainly polymers of glucose and fructose. Therefore, any enzyme which hydrolyzes the oligosaccharides should result in an increase of glucose and/or fructose, with a corresponding decrease in oligosaccharide fractions. Transglucosidase isolated from the same selected strain of Aspergillus niger var. was tested as described above by adding 20 transglucosidase units to the honeydew extract (0.5 ml volume). A unit of transglucosidase is defined as the amount of enzyme required to produce one micromole of panose per minute under the conditions of the assay in which maltose is used as the substrate. A copy of the HPLC chromatograms from this assay is shown in Figure 1 of the honeydew digest at zero time and after 17 hours. Figure 1 clearly shows the increase of the monosaccharides (glucose and fructose) as the oligosaccharides of honeydew are hydrolyzed. Example 2 Transglucosidase hydrolysis of sucrose, trehalulose and melezitose Honeydew is reported to contain sucrose, trehalulose, and melezitose (7). Since the HPLC conditions with the BioRad HPX-87H column hydrolyze sucrose, another HPLC column was found whose operating conditions did not cause hydrolysis of sucrose. BioRad Amino Bio Sil 5S column was found to give very good separation of the oligosaccharides and monosaccharides without hydrolyzing sucrose using mobile phase composed of 68 % (v/v) acetonitrile and 32 % (v/v) water. The column was operated at 25 °C with a mobile phase and a flow rate of 0.8 ml/min was used. A 20 µl sample of 4 % DS (dry substance) was found adequate for good separation. For enzyme digestion, 4 % solutions were made of each sugar (ACS grade or source indicated) in 0.02 M acetate buffer pH 5.0. The digestion was carried out at 50 °C using 10 ml of substrate and 50 units of transglucosidase. The reaction was terminated by incubating the digest in a boiling water bath for 10 minutes. Prior to injecting into the HPLC the digest was filtered through 0.45 micron filter. Figures 2-4 show the chromatograms of the hydrolysis of, respectively, sucrose, melezitose (SIGMA CHEMICALS) and trehalulose (Gift from V.B. MILLER, Clemson University) by transglucosidase. The results clearly demonstrated the hydrolysis of sucrose, trehalulose, and melezitose into glucose and fructose by the transglucosidase preparation. These observations are unique, because normally transglucosidase hydrolyzes maltose and transfers one glycosyl residue to another maltose forming 1-6 linkage, producing panose. What makes the hydrolysis of the three sugars sucrose, melezitose and trehalulose so unusual is that all are made up of glucose and fructose i.e. sucrose [gluc-fruc, αβ(1->2)], melezitose [αgluc(1->2)] β fruc (3->1) αgluc], and trehalulose [αgluc (1->1) fruc]. Example 3 Honeydew Hydrolysis by Commercial Pectinase Preparations Honeydew extract, obtained from contaminated ("Sticky") cotton as described in Example 1, was used to test various commercial enzyme preparations that contain various fungal enzyme activity. The same procedure as was described above in Example 1 was used to test these enzymes for hydrolytic activity on honeydew. To examine the development of the monosaccharide (glucose and fructose) as the result of honeydew hydrolysis, the reduction in the peak with RT of 7.22 was used as an indication of honeydew hydrolysis (see figure 1). A qualitative scale was developed to rate the effectiveness of the enzymatic hydrolysis of the honeydew by the various enzymatic compositions of the present invention. The scale developed ranged from 0 to 3 with 0 (-) indicating approximately 0-10 % hydrolysis, 1 (+) indicating approximately 10-40 % hydrolysis, 2 (++) indicating approximately 40-70 % hydrolysis and 3 (+++) indicating approximately 70-100 % hydrolysis. The results of these analyses are summarized in Table 1. Treatment of Honeydew with Different Enzymes and Enzyme preparations Enzyme Supplier Microbial Source Index of Hydrolysis Pectinase (CLAREX-ML) SOLVAY ENZYMES USA Aspergillus niger ++ Pectinase (PEAREX 5X) SOLVAY ENZYMES USA Aspergillus niger +++ Pectinase (Sumizyme-AP-II) SHIN NIHON CHEMICAL Japan Aspergillus niger +++ Transglucosidase L-1000 SOLVAY ENZYMES USA Aspergillus niger ATCC 14916 +++ Transglucosidase (Amano) AMANO INTERNATIONAL Japan Aspergillus niger +++ α-Galactosidase (BEANO) AK PARMA INC. USA Aspergillus niger + Transglucosidase α-1,4 SOLVAY ENZYMES USA Aspergillus niger ATCC 14916 + Example 4 Field application of pectinase enzyme composition Sumizyme-AP-II in it's liquid form was diluted to 2 % (v/v) of its original concentration, just prior to use, with tap water containing 0.25 % (w/v) TRITON® X-100 (UNION CARBIDE) whose pH was lowered to 4.5 by adding a sufficient amount of acetic acid. This mixture was applied to Bemisia tabaci honeydew-contaminated cotton at the time of harvest by spraying it with nozzles, such that the harvested seedcotton was wetted with this solution. Knowing the speed of the cotton picker, the pressure in the spray lines was adjusted to apply approximately 114 l (30 gallons (US)) of this mixture per acre of cotton. The yield of the fields where these tests were conducted was approximately 1360 kg (3,000 lb) seedcotton per acre. The picker used in these experiments, an International Harvester model 422, had a small (53 l/14 US gallons) plastic tank, a pressure regulator, ball-type flow valves and filter mounted near the driver to hold the enzyme solution. From this tank, the mixture was pumped to the nozzles at various pressures (approximately 0.28 MPa/40 psi) to produce the desired application rate. Spray nozzles were placed on boom mounts (metal support structures) in front of the picker heads so that the cotton was sprayed with a fine mist just prior to entering the picker (Boom Treatment). Another method of application which was used to test the pectinase preparation was spraying the harvested cotton via flush-mounted nozzles directed into the ducts which convey the harvested seedcotton from the picker heads to the storage bin (called a basket) behind the driver on the picker. Following spraying, samples were rapidly removed from the picker basket and placed into air-tight containers to determine applied moisture (and, thereby, the effective enzyme addition, since it is presumed that the enzyme must be in a wet state to be effective). These samples were then weighed, dried in a forced-air oven at 105 °C overnight, and reweighed to determine their moisture content. Untreated samples were likewise sampled and by comparison the effective addition of spray was determined. To determine the effect upon the honeydew sugars and the sticky nature of the harvested cotton, additional samples were taken from the picker basket, placed in tightly sealed and wrapped plastic containers (ZIPLOC® bags) which were incubated at ambient temperature (ca. 29-41°C/85-105 °F) for two days following which the seedcotton was removed from the plastic bags and dried in a hot, dry room (an unairconditioned greenhouse which ranged in temperature from ca. 46-71°C (115-160 °F) and was quite low in humidity) until their weight was constant. The samples were then ginned with a small laboratory-scale cotton gin and 10 g of the lint (i.e., cotton fiber) analyzed for sugars by HPLC. The remaining lint was sent to a laboratory (Dr. Henry H. PERKINS, Jr. in Clemson, S.C.) for analysis of reducing sugars and stickiness by the Minicard test. The later test, as employed in the United States, has a scale of 0 to 3 with 0 representing nonsticky cotton and 3 being the most sticky. Application of the pectinase enzyme composition resulted in a stickiness rating of 2.75 ± 0.29 (means ± SEM) being reduced in Boom applications to a rating of 0.5 ± 0.29. When sprayed into the Duct, the stickiness was lowered to a Minicard rating of 0.25 ± 0.00 and when sprayed from both locations, the stickiness rating was 0.00 ± 0.00. These results are summarized below in Table 2. The experiment illustrated in Table 2 and figures used unsprayed cotton as a control, which is reflected in the relative water content of the replicates (Table 2). Treatment Minicard Rating Percent Sugars Percent Moisture Check 2.75 ± 0.29 0.76 ± 0.06 0.15 ± 0.07 From Boom 0.50 ± 0.29 1.1 ± 0.11 5.60 ± 0.08 From Duct 0.25 ± 0.00 0.87 ± 0.02 12.65 ± 0.03 Boom + Duct 0.00 ± 0.00 0.57 ± 0.01 12.43 ± 0.33 Data represent means ± S.E. of four replicate samples. The treatment labeled check was picked without enzyme addition, the other treatments were sprayed at harvest with a solution which contained 2 % (v/v) of the enzyme preparation 0.25 % (v/v) surfactant in a weak solution of acetic acid (pH ca. 4.5). Example 5 Field application of transglucosidase enzyme composition Transglucosidase L-1000 was obtained from SOLVAY ENZYMES, INC. (Elkhart, IN) as a liquid which was diluted to various concentrations which ranged from 0.25 to 1 % (v/v), just prior to use, with tap water containing 0.25 % (w/v) TRITON® X-100 (UNION CARBIDE) whose pH was lowered to 4.5 by adding a sufficient amount of acetic acid. This mixture was applied to Bemisia tabaci honeydew-contaminated cotton at the time of harvest by spraying it with nozzles, such that the harvested seedcotton was wetted with this solution. Knowing the speed of the cotton picker, the pressure in the spray lines was adjusted to apply on the order of 114 l (30 gallons (US)) of this mixture per acre of cotton. The yields of the fields where these tests were conducted varied from approximately 730-1500 kg (1,600 to 3,400 lb) seedcotton per acre. International Harvester pickers, model 422 and model 782 were used in the experiments. The IH model 422 had a small (53 l 14 US gallons) plastic tank, a pressure regulator, ball-type flow valves and filter mounted near the driver to hold the enzyme solution. From this tank, the mixture was pumped to the nozzles at various pressures (approximately 0.28 MPa/40 psi) to produce the desired application rate. The IH model 782 used the picker's water supply tank (ca. 190 l/50 US gal) as a source of water for the spray. On both pickers, Spray nozzles were placed on boom mounts (metal support structures) in front of the picker heads so that the cotton was sprayed with a fine mist just prior to entering the picker (Boom Treatment). Another method of application which was used to test the transglucosidase L-1000 preparation was by spraying the harvested cotton via flush-mounted nozzles directed into the ducts which convey the harvested seedcotton from the picker heads to the storage bin (called a basket) behind the driver on the picker. Following spraying, duplicate samples were rapidly removed from the picker basket and placed into air-tight metal containers (double lip-seal 1 quart paint cans) to determine applied moisture (and, thereby, the effective enzyme addition, since it is presumed that the enzyme must be in a wet state to be effective). These samples were then taken to the laboratory, weighed, placed and dried in a forced-air oven at 105 °C overnight (for at least 8 hours), removed, cooled in a large desiccator-filled metal cabinet, and then reweighed to determine their moisture content. This % water calculation was done by ASTM test methods, using the wet weight as the denominator. Untreated samples, and samples which were sprayed with an equivalent amount of water plus acetic acid and TRITON® X-100 were likewise sampled and by comparison the effective addition of spray was determined. To determine the effect of the transglucosidase L-1000 preparation upon the honeydew sugars and the sticky nature of the harvested cotton, additional samples were taken from the picker basket, likewise placed in tightly sealed metal cans which were incubated at ambient temperature (ca. 29-41°C/85-105 °F) for various lengths of time, from 24 hours to 5 weeks, following which the seedcotton was removed from the metal cans and dried in a hot, dry room (an unairconditioned greenhouse which ranged in temperature from ca. 46-71°C (115-160 °F) and was quite low in humidity) until their weight was constant. The samples were then ginned with a small laboratory-scale cotton gin and 10 g of the lint (i.e., cotton fiber) analyzed for sugars by HPLC. The remaining lint was sent to a laboratory (Dr. Henry H. PERKINS, Jr., USDA-ARS, Clemson, S.C.) for analysis of reducing sugars and stickiness by both the Minicard test and the Thermodetector tests. Note that the Minicard test, as employed in the United States, has a scale of 0 to 3 with 0 representing nonsticky cotton and 3 being the most sticky and the Thermodetector test has a scale which is approximately 10-fold higher (i.e., a 3.0 Minicard rating is very close to a 30 thermodetector rating). While the these tests give equivalent results, the later is somewhat faster to administer with very sticky samples, and so was predominantly used to access stickiness during the 1993 compaign. Additional seedcotton lots were processed into cotton "modules" in the field after spraying with either the transglucosidase L-1000 solution or an equivalent amount of water containing acetic acid and TRITON® X-100 at the same rates used in the enzyme additions. These modules were stored under ambient conditions (ca. 21-41°C/70 to 105 °F) for approximately one week prior to being taken to a commercial gin for seed removal. Samples were removed from these commercial modules at time of their preparation, just prior to ginning and from the lint slide in the gin just after the seeds were removed. The stickiness in these samples at the time of ginning was : 21.67 ± 1.20 (mean ± SEM) for water-alone-treated samples removed from the module and ginned on a laboratory-scale gin; 0.00 ± 0.00 for transglucosidase L-1000 treated seedcotton; 4.10 ± 0.79 for water-treated seedcotton from the gin lint slide (i.e., immediately after seed removal); and 0.25 ± 0.16 for transglucosidase L-1000 treated seedcotton taken from the lint slide. Obviously, many modifications may be made without departing from the basic spirit of the present invention. Accordingly, it will be appreciated by those skilled in the art that, within the scope of the appended claims, the invention may be practiced other than has been specifically described herein. References 1 - BATES, R. B., D. N. BYRNE, V. V. KANE, W. B. MILLER and S. R. TAYLOR, Carbohydrate Res. (201), 342-345 (1990). 2 - HEUER B., Z. PLANT, Text. Res. J. 55(5), 263-6 (1985). 3 - TARCZYNSKI, N. C., Dn. N. BYRNE, and W. B. MILLER, Plant Physicol. 98 753-756 (1992). 4 - MILNERA, S. M., S. SISMAN., Melliand Textilber. , 70(11) E348-E349 (1989). 5 - PERKINS, H. H., Jr., Text Res. J., 53(8) 508-12 (1983). 6 - GRAY, A., N. C. NORTH, and A. N. WRIGHT., Cotton Fibers Trop. 40(2) 105-11 (1985). 7 - BRUNO, G. P., Industrial Cotonier 35 227-230 (1982). 8 - HENDRIX, D. L., Y. WIS., Proceedings of the Beltwide Cotton Production Conference, 2 671-673 (1992).

Claims: Use of at least one enzyme which is a transglucosidase, a pectinase or an α-galactosidase for the reduction of honeydew on sticky cotton contaminated with honeydew. The use of claim 1, wherein the enzymes include an enzyme derived from a fungal source. The use of claim 2, wherein the fungal source is a fungus of the genus Aspergillus. The use of claim 3, wherein the fungal source is a fungus of the species Aspergillus niger. The use of any one of claims 1 to 4 wherein the enzymes include a transglucosidase. The use of any one of claims 1 to 5, wherein the enzymes include a pectinase. A method for the treatment of cotton fiber having honeydew thereon, said method comprising contacting said cotton fiber with an enzymatic composition including at least one enzyme which is transglucosidase, a pectinase or an α-galactosidase and is capable of hydrolyzing at least one of the honeydew sugars of contaminated sticky cotton, whereby the honeydew is at least partially hydrolyzed and a reduction of the honeydew on the contaminated cotton is provided. The method of claim 7, wherein the enzymes include an enzyme derived from a fungal source. The method of claim 8, wherein the fungal source is a fungus of the genus Aspergillus. The method of claim 9, wherein the fungal source is a fungus of the species Aspergillus niger. The method of any one of claims 7 to 10, wherein the enzymes include a transglucosidase. The method of any one of claims 7 to 11, wherein the enzymes include a pectinase. The method of any one of claims 7 to 12, wherein the cotton has a percent moisture content of at least about 5.6% after application of the enzyme.

Inventors: LANTERO ORESTE J, SHETTY JAYARAMA K, LANTERO, ORESTE J., SHETTY, JAYARAMA K.
Applicants: GENENCOR INT, GENENCOR INTERNATIONAL, INC.
Application year: 1994
Main classification: D06L1
IPC codes: D06M16, C12S11, D06L1, C12R1, C12N9, C12P19, D01C1